Iodine‐Catalyzed C3–H Sulfinylation of Indoles with Sulfenamides

Organic sulfides, particularly 3‐sulfinylindoles, have garnered substantial attention owing to their remarkable pharmacological activities and broad applications in materials science and pesticide chemistry. Nevertheless, traditional synthetic approaches for 3‐sulfinylindoles usually suffer from drawbacks such as toxic reagents, dependence on transition‐metal catalysts, and severe reaction conditions. Herein, an iodine‐catalyzed C3–H sulfinylation strategy is presented for the synthesis of 3‐sulfinylindoles, employing sulfenamides as stable and odorless sulfenylating reagents. This protocol proceeds under mild conditions (100 °C in 1,2‐dichloroethane) without extra oxidants or additives, delivering a broad range of 3‐sulfinylindole derivatives in moderate to excellent yields. Substrate scope investigations demonstrate excellent compatibility with indoles having electron‐donating/withdrawing groups and sulfenamides containing aromatic/heterocyclic groups. This method addresses critical challenges in traditional sulfinylation, providing a green, metal‐free, and efficient approach for the construction of thiofunctionalized indole derivatives with potential applications in drug discovery and functional materials.